Method and apparatus for adjusting agricultural cultivator tynes

ABSTRACT

An agricultural tyne assembly is disclosed which uses a series of linkages to transfer loading from the tyne as deflection of the tyne occurs upon striking an obstacle during tilling. There is also disclosed means to adjust the spring loading on an agricultural tyne.

This is a division of application Ser. No. 397,683, filed July 13, 1982now U.S. Pat. No. 4,502,548.

This invention relates to agricultural cultivators and more particularlyto tyne assemblies for use on agricultural cultivators.

An agricultural cultivator normally consists of a substantiallyhorizontal tool frame upon which are fastened a plurality of soilengaging tynes. It is desirable that each of these tynes be individuallypivoted to the tool frame so that upon any one of the tynes striking anobstacle in use it may deflect backwards and upwards to pass over theobstacle and then return to its soil engaging position.

Many methods of obtaining such a stump jump function, as it is termed,have been proposed but in general these suffer from the problem thatinsufficient lift to pass over large obstacles is obtained and ifsufficient lift is available then the return pressure to allow the tyneto become soil engaging again is insufficient to complete the return ofthe tyne. For instance there has been proposed a tyne deflection systemin which a spring acts directly on the tyne so that a certain fixed loadacts upon the tyne point so that as the tyne is drawn through the groundit will not be deflected in normal use. Then, as the tyne deflects onstriking an obstacle the deflecting force increases as the springcompresses or expands depending on the positioning of the spring inrelation to the tyne and hence as the tyne passes over the obstacle thereturning force on the tyne greatly increases, and it may occur that theforce is such that the obstacle is driven forward rather than the tynepassing over the obstacle. If the tyne does pass over the obstacle thenduring the early part of the return path a strong returning force orrestoring force is obtained but as this tyne reaches its soil engagingposition again the returning or restoring force decreases and in factincomplete soil engagement may occur.

This problem exists with all types of ploughs and soil engagingimplements but in particular for chisel ploughs a force preventing thedeflection of the tyne when it is in the soil engaging position isrequired for some types of soil to be approximately 318 kilograms forceat the share point (about 700 pounds) but it is desirable that thisforce be greatly reduced as the tyne deflects.

It will be realised that different soils will require different soilengaging forces and hence a problem to be overcome by this invention isto provide for adjustment of the static restoring force when the tyne isin the ground engaging position.

It will be realised, too, that if a high degree of lift is obtained froma deflectable tyne then a very long and cumbersome spring is required toenable this deflection. It will be desirable therefore to have a shortermore manageable spring.

It is an object of this invention therefore to provide an agriculturalcultivator which has tynes adapted to deflect over large obstacles.

It is a further object to provide a spring tyne assembly adapted todeflect over large obstacles and in which the deflection force isinversely proportional to the degree of lift of the tyne from its normaloperating position.

It is also a further object of this invention to provide an agriculturaltyne having spring loading in which only a short travel of the springenables large deflection of the tyne to enable the tyne to pass overobstacles.

It is a further object to provide for adjustment of the soil engagingforce to allow for use of the agricultural implement for different soilor different ground types.

In one form therefore the invention is said to reside in a supportarrangement for a tyne of a type adapted to allow for a swing back ofthe tyne when encountering an obstacle within the ground and to providea restoring force to return the tyne to a tilling position after beingswung back, the means supporting the tyne being characterised byproviding for a restoring force that is less when the tyne is swung backthan when it is in the tilling position.

The restoring force for the tyne may be provided by means of a helicalspring or may be provided by a means of an hydraulic spring arrangement.

In a preferred form of the invention there may be further includedadjustment means whereby to provide for variation of the staticrestoring force, that is, the restoring force when the tyne is in thetilling position for when the tyne is used in different soil or groundtypes.

This adjustment means may be provided by means of screw threadedadjustment means acting on a pressure rod positioned between the springand the tyne.

In an alternative form, when the restoring force is provided by ahelical spring the adjustment means may comprise a pressure rod uponwhich the spring acts and a collet and shoulder or abutment arrangement,a plurality of the shoulders being provided along the pressure rod, thecollet being adapted to abut onto any one of the shoulders so as toprovide a plurality of discreet spring tensions and hence staticrestoring forces.

This adjustment means may further include a traveller adapted to travelalong the pressure rod, the spring abutting the traveller on one facethereof, the traveller having a shaped opposite face adapted to co-actwith the collet and the collet having a complimentary shaped face to theopposite face such that when the traveller abuts the collet the colletmay not be removed laterally. That is, the collet may not slide out orfall out but that the spring loading must be removed before the colletcan be moved.

There may be further included adjustable means engageable between thetraveller and the pressure rod or an abutment on the pressure rod suchthat the spring may be compressed so as to allow for removal of thecollet and adjustment of the spring pressure.

There may be further included adjustable means engageable between thetraveller and the pressure rod or an abutment on the pressure rod suchthat the spring may be compressed so as to allow for removal of thecollet and adjustment of the spring pressure.

In an alternative form of the invention the invention may be said toreside in an agricultural tyne assembly of a type having a tyne adaptedto deflect to clear obstacles, the tyne being pivotable about a mountingmeans affixed to a tool support frame, the tyne being loaded by springpressure means and including a spring pressure rod to give resistance tooppose deflection of the tyne, characterised in that the tyne assemblyincludes a pair of link arm means, said link arm means being pivotallyconnected to one each of their respective ends to the spring pressurerod and the other ends of the link arm means being pivotally connectedto the tyne and the mounting means respectively such that when the tyneis in a non-deflected position the spring pressure acts onto the tynethrough the link arm means attached to the tyne but its spring pressureduring deflection of the tyne is transferred from the link arm meansattached to the tyne to the link arm means attached to the mountingmeans such that the spring pressure loading on the tyne is reducedduring deflection of the tyne from a tilling position.

In the normal soil engaging or tilling position, force from the springacts straight down the pressure rod onto the link attached between thepressure rod and the tyne and hence onto the tyne, but as deflection ofthe tyne occurs the line action of the force is varied as the spring iscompressed so that progressively the spring deflection force is taken onthe link connected between the spring pressure rod and the mountingmeans so that the actual force on the share point is reduced as the tyneis swung backwards.

By this means the actual deflection of the spring is small for the fulldeflection of the tyne.

The spring referred to in this embodiment may be a helical type springor an hydraulic spring.

On this embodiment too there may be further included adjustment means onthe spring pressure rod whereby to vary the spring loading on the tynefor different soil types.

In a further form the invention may be said to reside in a springtension adjustment system for use with a spring loaded agricultural tynewherein the spring is of a type acting along a spring pressure rod, andadjustment means is provided on the pressure rod whereby to vary thespring tension characterised in that the adjustment means comprises aplurality of shoulders on the pressure rod and a collet abutable againstone of the shoulders whereby to provide a series of discreet springtension adjustments.

In a preferred form of this form of the invention the spring tensionadjustment system may include a traveller adapted to travel along thepressure rod and upon which the spring directly acts, the travellerhaving a face adapted to co-act with the collet such that when thetraveller abuts the collet the collet may not be removed from theshoulder by an application of a direct lateral force.

In a preferred form of this part of the invention there may be furtherincluded spring tension adjustment means engageable between thetraveller and the pressure rod such that the spring may be compressedfor adjustment. The adjustment means may include an hydraulic jack toprovide for compressing the spring for removal of the collet.

In a further form of the invention the invention may be said to residein a method of adjusting spring tension acting on a spring pressure rodwherein the tension is variable in discreet steps by means of a colletengageable in one of a plurality of shoulders along the spring pressurerod, the method comprising the steps of providing spring compressionmeans between the spring and an abutment on the spring pressure rod,compressing the spring so as to allow removal of the collet from one ofthe shoulders, expanding or compressing the spring further as required,placing the collet against the required shoulder and allowing the springto expand against the collet and hence the required shoulder.

In a preferred form of this form of the invention the spring compressionmeans may include an adjustment assembly including an hydraulic jack toprovide the compressive force for the compression of the spring.

In a further form the invention may be said to reside in an agriculturalimplement having a tool frame and a plurality of tyne assemblies on thetool frame, the support arrangement of the tynes being characterised byany of the above preferred embodiments of the invention.

It will be seen therefore that by means of this invention there isprovided a tyne asembly for an agricultural implement which has adeflectable tyne, the loading of which is reduced as the tyne is swungbackwards. There is also provided adjustment means to adjust the staticrestoring force on the tyne.

To more clearly understand the invention however reference will be madeto the accompanying illustrations in which several embodiments of theinvention are disclosed.

FIG. 1 shows a cutaway front view of one embodiment of the tyne.

FIG. 2 shows a cutaway view of an alternative embodiment of the tyne.

FIG. 3, FIG. 4, and FIG. 5 show a side view of the embodiment of thetyne shown in FIG. 1 at various stages of deflection.

FIG. 6 shows a side view of the embodiment shown in FIG. 2 with the tynein the tilling position.

FIG. 7 shows a rear quarter view of the embodiment of the tyne shown inFIG. 1 particularly showing the spring tension adjustment means.

FIG. 8 shows a rear quarter view of the embodiment of the tyne shown inFIG. 2 particularly showing an alternative tension adjustment means.

FIG. 9 shows a view of the spring tension adjustment system using acollet and abutment shoulders.

FIG. 10 shows a spring tension adjustment device according to theinvention and

FIG. 11 shows an alternative view of the spring tension adjustmentdevice according to the invention.

Now looking in more detail at FIG. 1, the tyne assembly is mounted on atool frame bar 2, shown cutaway. The tyne assembly consists of a blade3, a tyne arm 4, the arm 4 being pivoted about pivot point 14, at theupper end of the arm 4 are welded plates 5 having a flat upper surface 6which abut underneath the tool frame 2 when the arm is in the tillingposition.

A spring support assembly 7 supports a spring 8 which bears onto thetyne arm through the spring pressure rod 9 and the spring pressure rodto tyne link 10. A further link 11 extends from the spring pressure rodto a pivot point 12 on the mounting plate 13.

The spring tension adjustment means in FIG. 1 is by means of a nut 15travelling on a screw thread 16.

FIG. 2 shows an alternative embodiment having different adjustment meansand in this means a series of shoulders or abutments 22 are formed onthe lower end of the pressure rod 9' and a collet 31 abuts one of theseshoulders and is abutted against by the spring 8.

Now looking at FIGS. 3, 4, and 5 to show the progressive deflection ofthe tyne, it will be seen that in FIG. 3, the tyne is in its tillingposition with the plate 5 abutting up against the tool frame 2. At thisstage the spring 8 acts directly down the spring pressure rod 9 and itssaddle 25 and pivot 19 onto the link 10 and directly onto the arm 4. Atthis stage the link 11 will be taking little or no load.

As shown in FIG. 4 as the arm 4 is deflected it pivots about the pivotpoint 14 and the line of action of the force exerted by the spring 8 isnow divided between the link 10 and the link 11.

As shown in FIG. 5 when the arm 4 has reached its uppermost position thespring 8 has its force acting almost directly down through the link 11onto the mounting plate 13. The link 10 would in fact be taking verylittle load onto the tyne arm 4.

The uppermost limit of the travel of the tyne arm 4 occurs when theplate 5 abuts by means of the abutment 20 onto the back of the toolframe 2.

It will be seen that by reference to FIGS. 3, 4, and 5 that while thetyne has deflected through almost 90° the actual compression of thespring as can be seen by the upper extension 21 of the spring pressurerod 9 extending above the spring support assembly 7. This means that arelatively short and non-cumbersome spring can be used to provide allthe necessary returning or restoring force for the tyne.

FIG. 6 shows an alternative embodiment of the adjustment means in whichthe pressure rod 9' has a plurality of shoulders or abutments 22 againstone of which a collet 31 abuts.

A traveller 32 has the spring 8 abutting on one side of it and abuts thecollet 31.

FIGS. 7 and 8 show rear views of the tyne assembly and in these figuresnumbers refer to the numbers from the earlier discussion.

An important point to note is that the lower end of the pressure rod 9has the saddle 25 through which the pin 19 passes, the links 10 and thelinks 11 are both pivoted to this pivot 19 but are not rigidlyrotationally fixed one to the other. A further pivot point 26 is alsoprovided at the lower end of the link between the pressure rod and thetyne arm 4.

Now looking at FIG. 9 it will be seen that the pressure rod 9' includesa series of abutments 22 and on the uppermost abutment there is a collet31 being forced against a shoulder or abutment 30 by means of thetraveller 32 which in turn is forced down by means of the spring 8.

It will be seen that the traveller 32 has a shaped lower end 33 and thecollet 31 has a correspondingly shaped face 34 such that once the colletis in position it cannot be removed directly sideways but in fact thetraveller must be lifted slightly before the collet may be removed.

In fact the collet 31 is of an approximately horse shoe shape so that itmay be slid on and off the respective shoulders.

Compression of the spring 8 is achieved by means of providing aexpansion force between the abutment 35 on the traveller 32 and thesleeve 36 on the pivot pin 19. This force is provided by means of thearms 37 and 38 acting onto the abutment 35 and the sleeve 36respectively.

FIG. 10 shows the type of device which may be used to provide theexpansion force for the spring.

The adjustment device generally shown as 40 comprises a base 41 and anupright 42 rigidly affixed to the base. The arm 38 is firmly attached tothe base 41.

A sliding arrangement 43 may slide up and down the upright 42 and thisslider 43 carries the arms 37 which engage under the shoulder 35 on thetraveller 32.

An hydraulic jack 44 of any known type may be used to provide theexpansive force between the base 41 and the slider 43. Transmission ofthe force from the hydraulic jack is assisted by means of the braces 45extending down to the arms 37. A handle 46 is provided on the top of theupright 42 to assist in carrying and positioning the adjustment device40.

Adjustment of the spring tension using the screw thread arrangement issuch that for a complete agricultural implement to adjust all the springtensions on all of the tynes on an agricultural implement it may take acomplete days work whereas by use of this proposed adjustment device thetime to complete this operation may be greatly reduced.

In one particular embodiment of the deflecting tyne and cultivating tyneaccording to this invention the spring on the tyne provide a restoringforce to resist cultivating forces at the share point in excess of 318kilograms force but the system of linkages is such that the tyne sharepoint is allowed to deflect to lift over obstacles of a height ofapproximately 500 millimeters or 20 inches. Over the first portion oftyne deflection of 15 degrees or 23 millimeters clearance under theshare point the resistance to deflections increases from 318 kilogramsand decreases back to approximately 318 kilograms force but that asdeflection increases up to 35 degress or 123 millimeters under the sharepoint the resistance to deflection reduces to 257 kilograms force (565pounds). This should ensure sufficient penetration effort to return thetyne share to its normal operation position.

From the 15 degree deflection position the share resistance forcedecreases in a straight line in proportion to the angular deflection ofthe tyne to a maximum return load of 57 kilogram force (125 pounds) whenthe tyne has deflected 73 degrees or 500 millimeters clearance under theshare point. This reduction in the resistance force at the share is aresult of the redistribution of the increasing spring load which wouldnormally be applied to the tyne to the secondary arcuate linkage whichabsorbs this increase internally.

In this embodiment the actual spring compressive movement to achieve thedesired maximum share lift of 500 millimeters has been reduced from 248millimeters (93/4 inches) which is impractical to achieve to 88millimeters (31/2 inches).

It should be noted that by the use of the present invention advantagesover conventional spring actuating systems are obtained and inparticular for chisel plough tynes high share lift clearance isobtained, there is reduced wear on pressure rod guide components, thereis an economy of spring design and a reduction in tyne deflection forcesat the share point to reduce return impact loads.

Taking this last point the reduction in the tyne deflection forces atthe share point which reduce return impact loads mean that design of thetyne arms may be advantageously altered. Conventional chisel plough tynearms are normally 51 millimeters (2 inches wide) and in the soilengaging area the wrap around of the share increases this width toapproximately 65 milimeters (21/2 inches). As the width of the tyne inthe area of the share has a major influence on the draught requirementsof the tractor to tow the agricultural implement any reduction in widthin this area will reduce the draught force necessary and consequentlyreduce fuel consumption of the operation. In the present invention thetyne may be made from a material section of 65 millimeters by 20millimeters with a width at the wrap around the share area of a maximum36 millimeters. This reduces the face width in this area by 45 percentwith a corresponding reduction in draught force necessary.

The claims defining the invention are as follows; I claim:
 1. A methodof adjusting spring tension acting on a spring pressure rod in anagricultural tyne wherein the tension is variable in discreet steps bymeans of a collet abuttingly engageable against any one of a pluralityof shoulders along the spring pressure rod, the method comprising thesteps of providing a hydraulic jack spring compression means between thespring and an abutment on the spring pressure rod, compressing thespring with the hydraulic jack so as to allow for removal of the colletfrom one of the shoulders, expanding or compressing the spring furtheras required, placing the collet against the required shoulder andallowing the spring to expand against the collet and hence the requiredshoulder.
 2. A spring tension adjustment system for use with a springloaded agricultural tyne wherein the spring is of a type acting alongthe spring pressure rod, an adjustment means is provided on the pressurerod whereby to vary the spring tension, characterized in that theadjustment means comprises a plurality of shoulders on the pressure rod,a collet abuttable against any one of the shoulders to provide a seriesof discreet spring tension adjustments, and means independent of thecollet engageable between the spring and the pressure rod such that thespring may be compressed for adjustment, said independent meansincluding a hydraulic jack adapted to provide the spring compressiveforce.
 3. A spring tension adjustment system as in claim 2 wherein thespring includes a traveller adapted to travel along the pressure rod andupon which the spring directly acts, the traveller having a face adaptedto co-act with the collet such that when the traveller abuts the colletthe collet may not be removed from the shoulder by the application of adirect lateral force.